![]() Visual inspections and progress monitoring only need relative accuracy. Once your house is built, if you were to measure the same point from the roof to the ground, it would measure 30 feet. The measurement from the roof to the ground is 30 feet in the model. You are building your dream home, and the architect renders a 3D model of the plans. If a distance between two points measures 20 inches in the real world, it measures 20 inches on the map. It is the degree to which a given point on a map is accurate relative to other points on the same map. Relative accuracy is also known as local or internal. Accuracy- meaning how close a value is to its true value.” Will Fastabend, FlyGuys project manager. Precision – meaning how repeatable a measurement is. But if our absolute accuracy is low, comparing that same 100 acres over time over many maps may not be very precise. Say we map a 100-acre stockpile yard if our internal accuracy is good, we can make precise measurements on that job. “Internal accuracy refers to your accuracy to a specific map. ![]() If any legal issues arise over land disputes that need to be settled in court, the drone mapping information must be highly accurate, thus the term survey grade. Stamped by a licensed surveyor, survey-grade accuracy is typically needed for land development, drainage, or surveying floodplains. When a project calls for survey-grade accuracy, the accuracy of the measurements must hold up in court for legal arbitration. But before we get into it, let’s understand the meaning of survey-grade accuracy. We will look at the two degrees of accuracy in-depth and discuss examples of when relative accuracy is acceptable over absolute. So if relative accuracy can suffice, relative accuracy is as accurate as you need to be. Absolute accuracy is more time-consuming and costly, requiring heavier equipment and more advanced technology. Though it seems evident that greater accuracy is always better, it is not always the case, depending on the project. Some projects require a high level of accuracy, while others may not. Intended outputs, the map use, and the decisions made from the mapped information will tell you how accurate the data needs to be. Both are essential in determining measurement accuracy, but other factors will dictate how much is needed. In the world of drone mapping, accuracy is either relative or absolute. Please contact us and let us help you in any area of surveying.When Accuracy Matters Whether relative or absolute, accuracy can vary greatly In an increasingly digitised world, our drones provide the ability to easily and accurately capture your site and gain all the benefits of computer modeling and analysis for planning or monitoring your projects. This can be anything from basic distance and area calculations right up to stockpile volume analysis, sightlines or measuring the grade of a surface for road planning or water runoff. These outputs are fully geo-referenced and ortho-rectified meaning measurements and calculations can be taken directly from them. We recognise that our clients sometimes want a simple photograph to see chronological progress on their projects. Moreover, these photos can be used for progress reporting and especially for quantity surveyors who often have to call up site foremen and engineers to update them on monthly progress. DSM, DTM) and the accuracy of the 3D data is generally around 5cm laterally and 5-8cm vertical. We can also process the data to deliver full 3D terrain models (e.g. The resolution of our maps is usually 3.5cm per pixel (3.5cm GSD), which is enough to see a golf ball or matchbox, and if required we can provide higher resolutions. Unlike satellite data we operate on an on-demand basis, and our drones fly quite low and so aren’t affected by cloud. Drones provide the ability to capture on-demand maps for a fraction of the cost of traditional approaches using manned aircraft, and at a much higher resolution than satellites. Our core business at David Whelan Enterprises is the professional and reliable delivery of high-quality mapping data.Īgain, we provide this in the world of aerial mapping.
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